Method for providing heat from an oxidation process and from electrical energy

ABSTRACT

The present invention relates to a method for obtaining a hydrocarbon-containing gas, comprising the generation of heat by operating an apparatus for the oxidation of a hydrocarbon-containing gas, characterized in that alternatively a required provision of heat from the oxidation of the hydrocarbon-containing gas is substituted by the provision of heat from electrical energy with an apparatus for providing heat by using electrical power and the hydrocarbon-containing gas that is not oxidized is provided. A facility for carrying out the present method is also described.

The present invention relates to a method for obtaining ahydrocarbon-containing gas, comprising the generation of heat byoperating an apparatus for the oxidation of a hydrocarbon-containinggas.

The use of renewable energy sources, such as wind power, solar energyand hydropower, is gaining ever-increasing significance for thegeneration of electricity. Electrical energy is typically supplied to amultitude of consumers over long-ranging, supra-regional andtransnationally coupled electricity supply networks, referred to aselectricity networks for short. Since electrical energy as such cannotbe stored to a significant extent, the electrical power fed into theelectricity network must be made to match the consumer-side powerdemand, known as the load. As is known, the load fluctuatestime-dependently, in particular according to the time of day, the day ofthe week and also the time of year. Classically, the load variation isdivided into the three ranges, base load, medium load and peak load, andelectrical energy generators are, according to type, suitably used inthese three load ranges. For a stable and reliable electricity supply, acontinuously adjusted balance of electricity generation and electricityconsumption is necessary. Possibly occurring deviations are balanced outby what is known as positive or negative control energy. Positivecontrol energy is required when the normal electricity supply falls toofar short of the electricity demand at a particular time, in order toprevent an undesired fall in the network frequency and a breakdown inthe supply of electricity caused as a result. Negative control energy isrequired when there is an unexpected surplus of generated electricalpower, with the consequence of an undesired increase in frequency. Inthe case of regenerative electricity generating devices, the difficultyarises that, in the case of certain types, such as wind power and solarenergy, the energy generating capacity is not available at all times andcannot be controlled in a specific way, but is for example subject totime-of-day and weather-dependent fluctuations, which are predictableonly to a limited extent.

Against this background, there are increasing attempts to findpossibilities of balancing out discrepancies between energy provisionand energy consumption that occur due to the use of renewable energysources (renewables), in particular wind power and solar energy.

The possibilities proposed so far for storing the electrical energyavailable at times with a great surplus are to convert the same intochemical energy, for example the electrolysis of water into oxygen andhydrogen and/or the production of methane from carbon dioxide andhydrogen, referred to hereafter as methanation.

The laid-open patent application DE 10 2009 007 567 A1 discloses amethod for producing methanol by using carbon dioxide from the waste gasof fossil fuelled power generating plants, combined heat and powergenerating plants or other CO₂ emitters, the CO₂ being subjected to amethanol synthesis with hydrogen, which is preferably generated from anelectrolysis with regeneratively obtained electrical energy, inparticular in phases of low load of an associated electricity network.The synthesized methanol can be temporarily stored in a methanolreservoir or be fed as fuel to a heating or electricity generating powerplant. An energy generating plant carrying out the method comprises acombined heat and power generating plant, a wind, water and/or solarpower plant, an electrolysis plant, a reservoir for each of CO₂, O₂ andH₂, a methanol synthesis plant, a methanol reservoir and a controlsystem, in order to control these plant components for energy generationin dependence on the electricity demand to achieve optimum utilization.

The laid-open patent application DE 43 32 789 A1 discloses a method forstoring hydrogen energy by reaction of hydrogen, obtained for example byusing solar or nuclear energy, with carbon dioxide to methane ormethanol, which can then be used for example as a fuel for transportmeans or combustion facilities.

The laid-open patent application DE 10 2004 030 717 A1 discloses amethod and a device for converting and storing regeneratively obtainedenergy by means of conversion into chemical energy by using electricalenergy and carbon dioxide, the chemical energy being delivered again aschemical and electrical energy demand-dependently. For this purpose, aprocess cycle is provided, in which energy from a geothermal orregenerative source is converted into electrical energy, which is fed toa consumer and an electrolysis device. The hydrogen obtained by theelectrolysis is partly fed to a consumer and partly subjected to asynthesis with CO₂ from a CO₂ reservoir to form a hydrocarbon and analcohol. The hydrocarbon, for example methane, is stored in anassociated reservoir and partly fed to a consumer, partly fed to acombustion heating process, to which on the other hand oxygen from theelectrolysis is fed. By a thermodynamic process, the combustion heatingprocess generates electrical energy, which is partly fed to theelectrical consumer and partly fed to the electrolysis process. CO₂generated in the combustion heating process is stored similarly to CO₂that originates from a CO₂ recovery process, which is supplied with CO₂from the hydrocarbon consumer.

In a way similar to the documents presented above, the document WO2010/115983 A1 also describes an energy supply system with anelectricity generating device for the regenerative generation ofelectrical energy that can be fed into an electricity supply network, ahydrogen generating device for generating hydrogen by using electricalenergy of the regenerative electricity generating device, a methanationdevice for converting hydrogen generated by the hydrogen generatingdevice and a fed carbon oxide gas into a gas containing methane, and agas providing device for providing an additional gas or a substitute gasin a variably specifiable additional/substitute gas quality suitable forfeeding into a gas supply network by using the methane-containing gasfrom the methanation device and/or the hydrogen from the hydrogengenerating device.

The proposals presented above require very high investments, on thebasis of the storage capacity provided. These high investments aresolely attributable to the large number of components for carrying outthe respective methods. Another great disadvantage is the highmaintenance and servicing costs, attributable to the complexity of theaforementioned plants.

Furthermore, the overall efficiency for these plants and methods is verylow, since at least two reactions are necessary for obtaining methanefrom carbon dioxide and hydrogen, specifically the generation ofhydrogen from water and the conversion of the hydrogen obtained withcarbon dioxide. The nature of the intended use has further adverseeffects. The aforementioned possibilities for storing electricity servefor balancing out fluctuations in the generation of electricity fromrenewable energy sources, which may be very extensive. However, chemicalreactions can only be operated economically at high, sustained levels ofutilization. Below this high level of utilization, thecost-effectiveness and efficiency drop. For these reasons, thetechniques described in the publications have not become established inpractice, although the problem of efficient storage of electricityobtained from renewable energy sources has been a matter of discussionsince at least 1993, reference being made in this connection to thepriority date of the document DE 43 32 789 A1.

In view of the prior art, it is thus an object of the present inventionto provide an improved method for using or chemically storing electricalenergy that is not affected by the disadvantages of conventionalmethods.

In particular, it was an object of the present invention to find ways ofmaking it possible to reduce the expenditure on apparatus and operationwith regard to the storage, transport and use of electrical energy ascompared with the prior art.

Furthermore, it should be possible for the method to be scalable, sothat relatively small facilities, which may also be of a modularconstruction, can be used for carrying out the use or chemical storageof even small surpluses of electrical energy. Furthermore, decentralizedoperation of the facilities required for carrying out the method shouldbe possible.

The method should also have the highest possible efficiency.Furthermore, the method according to the invention should allow itselfto be carried out using infrastructure that is conventional and stillavailable.

In addition, the method should allow itself to be carried out with thefewest possible method steps, but they should be simple andreproducible.

Furthermore, implementation of the method should not involve any risk tothe environment or human health, so that it should be possible tolargely dispense with the use of toxic substances or compounds thatcould involve disadvantages for the environment.

Further objects that are not explicitly mentioned arise from the overallcontext of the following description and the claims.

These and further objects that are not expressly mentioned but can bereadily deduced or inferred from the circumstances discussed at thebeginning are achieved by a method with all of the features of patentclaim 1. Expedient modifications of the method according to theinvention for obtaining a hydrocarbon-containing gas are affordedprotection in the dependent claims 2 to 27.

The subject matter of the present invention is accordingly a method forobtaining a hydrocarbon-containing gas, comprising the generation ofheat by operating an apparatus for the oxidation of ahydrocarbon-containing gas, which is characterized in that alternativelya required provision of heat from the oxidation of thehydrocarbon-containing gas is substituted by the provision of heat fromelectrical energy with an apparatus for providing heat by usingelectrical power and the hydrocarbon-containing gas that is not oxidizedis provided.

This succeeds in an unforeseeable way in providing a method of theaforementioned generic type that has a particularly good set ofproperties, while the disadvantages of conventional methods can belargely avoided.

In particular, it has been found in a surprising way that it is therebymade possible to transform electrical energy that has been generated forexample from renewable energy sources, including wind power orphotovoltaics, into a storable form by means of the present method.

The method allows a hydrocarbon-containing gas, preferably natural gas,to be provided without expensive large-scale plants having to beconstructed and maintained for this. On account of the small number ofsteps and the high efficiency with which electrical energy can beconverted into thermal energy and used efficiently, the overallefficiency of the present method for obtaining a hydrocarbon-containinggas is very much higher than the overall efficiency of the methods ofthe prior art described in the introductory part of this application forobtaining a hydrocarbon-containing gas, preferably methane. Much lowerinvestment costs are necessary here than in the case of methanation.

Furthermore, methanation is carried out at very high temperatures, sothat, to increase the efficiency, the waste heat produced must berecovered. However, this involves a very high level of expenditure.

The present method can be operated very dynamically in comparison withmethanation, so that a hydrocarbon-containing gas can be obtained in avery short time without losses of efficiency. Furthermore, the method ofthe present invention can be carried out in a decentralized manner. Thisallows the method also to be carried out during servicing work on partof the plants that are used for providing a hydrocarbon-containing gas.

In addition, it is possible to convert existing plants in a relativelysimple way, so that, with a small investment expenditure, great savingsin natural gas are possible by expedient use of “surplus” electricity.

Furthermore, the present method allows the real option value to beincreased, since it allows gas and electricity to be exchangeable, sothat both control energy for the gas network and control energy for theelectricity network can be provided.

In addition, the method can be carried out with relatively few methodsteps, but they are simple and reproducible.

Furthermore, implementation of the method does not involve any risk tothe environment or to human health, such that is possible to dispenselargely with the use of toxic substances or compounds that could involvedisadvantages for the environment.

The method of the present invention serves in particular for obtaining ahydrocarbon-containing gas. A hydrocarbon-containing gas is understoodaccording to the invention as meaning a gas that comprises highproportions of hydrocarbons. These gaseous hydrocarbons include, inparticular, methane, ethane, propane, ethene, propene and butene. Apartfrom gaseous hydrocarbons, the gas may also comprise other gaseouscompounds. The hydrocarbon-containing gases particularly includenaturally occurring and/or synthetically produced natural gas.Generally, the hydrocarbon-containing gas that is used may have aproportion of methane, ethane, propane, ethene, propene and butene,preferably a proportion of methane that is at least 50% by volume, withpreference at least 60% by volume and with particular preference atleast 80% by volume.

The present method serves for obtaining a hydrocarbon-containing gas.Within the scope of the present invention, the term “obtaining” means inparticular that control over, possession of and/or ownership of this gasis/are gained. Ownership of a gas is not gained by a gas simply notbeing drawn from a gas line. Rather, a hydrocarbon-containing gas isobtained if physical and/or legal control over gas that is conservedwhen it is not consumed is achieved, for example possession orownership. This may be the case for example if a hydrocarbon-containinggas is provided by a supplier under long-term delivery contracts and thegas has to be taken. Furthermore, however, the term obtaining alsocomprises a conserved gas over which the operator of the methodaccording to the invention has control or which was previously in thepossession and/or ownership of that operator.

The present invention comprises the generation of heat by operating anapparatus for the oxidation of a hydrocarbon-containing gas. Theapparatus for the oxidation of a hydrocarbon-containing gas is notsubject to any specific restrictions, thus covering gas burners, gasmotors and gas turbines. Gas burners with low or high output may be usedhere, such as for example monobloc burners, which generally have anoutput of up to 10 MW, or larger burners, which often comprise aseparate blower. Furthermore, the gas burner may have a separateignition burner. Accordingly, the gas burner may be used in simple gasheaters or in devices for generating steam by burning gas.

Preferably, the apparatus for the oxidation of a hydrocarbon-containinggas may comprise a combined heat and power generating plant.Furthermore, the method of the present invention may be used in aunit-type cogenerating plant. The combined heat and power generatingplant or the unit-type cogenerating plant may comprise here a gas motorand/or a gas turbine.

The use of a combined heat and power generating plant for carrying outthe present method allows surprising advantages to be achieved, inparticular with regard to the energy required for the provision of heat.Based on the gas that is used for generating heat and electricity, theuse of electricity instead of gas can achieve efficiencies of over 100%,these high efficiencies being achieved in particular because even in acombined heat and power generating plant waste heat that cannot beexpediently used is produced. Furthermore, based on the gas that isobtained or can be provided in a combined heat and power generatingplant, relatively low outputs are necessary for heat generation. Since acombined heat and power generating plant generates not only heat butalso electricity, considerable gas can be provided even with arelatively low installed capacity of the apparatus for providing heat byusing electrical power. Here it should be taken into consideration thatproviding electricity from a combined heat and power generating plant isnot expedient when there is a great supply of electricity from renewableenergy sources, since surplus electricity cannot be easily stored. Inthe case of a combined heat and power generating plant which, on thebasis of the energy content of the gas that is used, generates about 40%electricity, 40% useful heat and 20% waste heat, the installation of aheating capacity of the apparatus for providing heat by using electricalpower of 40% is sufficient to substitute the useful heat output that isprovided by the combined heat and power generating plant. On the otherhand, however, the output of 100% of the gas required for this isconserved, and can be provided.

Preferably, therefore, the ratio of the installed heating capacity ofthe apparatus for providing heat by using electrical power to the totalcapacity of the combined heat and power generating plant may lie in therange from 1:1 to 1:10, with preference 1:1.5 to 1:5 and with particularpreference 1:1.8 to 1:4. The total capacity of the combined heat andpower generating plant is calculated here from the consumption of gas,and consequently represents the potential for providing gas by the useof electricity from renewable energy.

Surprisingly, the present invention in combination with the use ofcombined heat and power generating plants also offers the advantage ofbeing able to reliably make electricity available even in a network witha high proportion of energy from renewable sources. Energy fromrenewable sources cannot be provided on a planned basis. However, thenecessary storage facilities are relatively expensive, so that, whenthere is a low supply of energy from renewable sources, in particularsolar or wind power, conventional plants are used. With the use ofcombined heat and power generating plants, a very considerable amount ofgas is conserved at times when there is a high supply of energy fromrenewable sources, since the plant can be shut down, while the heatrequirement can be covered by the use of electricity. This gas can,however, be used for electricity generation at times of a low supply ofenergy from renewable sources, so that it is possible to counteract inan economical way the planning uncertainty that is involved in the useof renewable energy sources.

Apart from the aforementioned provision of heat from the oxidation ofthe hydrocarbon-containing gas, the present invention also comprises anapparatus for providing heat by using electrical power.

The apparatus for providing heat by using electrical power is notsubject to any specific limitations. Accordingly, the apparatus forproviding heat by using electrical power may for example transformelectrical energy into heat by resistance heating and/or inductionheating. Furthermore, electrical energy may be converted into thermalenergy by microwaves, so that the apparatus for providing heat by usingelectrical power may generate microwaves.

Preferably, a thermoelectric heating system can take power from thenetwork in large amounts, i.e. between 0.5 MW and 1 GW, with preference1 to 500 MW. A single component can achieve this thermal output here.According to a preferred embodiment, these outputs may, however, beprovided by a common group (“pool”) of multiple units, some of which arespatially separate, these separate units preferably being controlled bya central control device.

Furthermore, the taking of power from the electricity transmissionnetwork or the provision of electrical energy by an energy plant, forexample a wind power or solar power plant, can be varied over time andin the power output, so that a very short-term reaction to changes inthe supply of electricity or in the load of the network are possible. Itshould be stated here that the heat to be provided in a specific periodof time can possibly be provided by the oxidation of gas. This allowsthe security of supply for the end users or major customers to besafeguarded.

Apparatuses and devices that have low wear and require little servicingare preferably used for carrying out the present invention. Furthermore,the by the apparatuses for generating heat are preferably designed suchthat they are not subjected to overload.

The type of apparatus for generating heat by the oxidation ofhydrocarbon-containing gas or by the use of electrical energy is notcritical. What is important is that the heat that is obtained by theelectricity can replace or substitute the heat that is obtained by theoxidation of gas.

The degree of substitution, that is to say the proportion of thermalenergy that can be substituted by the use of electrical energy, is notcritical here. Thus, the ratio of the heating capacity achievable by gasto the heating capacity that is provided by electrical energy may lie inthe range from 100:1 to 1:100, preferably in the range from 10:1 to1:10, with particular preference in the range from 5:1 to 1:5 and withspecial preference in the range from 2:1 to 1:2.

With a very similar heating capacity of both apparatuses for generatingheat, a very high degree of substitution can be achieved, so thatsurprising economic advantages can be achieved.

The possibility of generating necessary thermal energy alternatively byelectrical energy or by the oxidation of a hydrocarbon-containing gasmeans that there is joint control over the apparatus for providing heatby using electrical power and the apparatus for the oxidation of ahydrocarbon-containing gas, so that a required amount of heat can beobtained alternatively by electrical energy or by oxidation of gas.

The term control should be understood here in a comprehensive sense, sothat simple manually controlled switching over and/or switching on ofthe at least two units for generating thermal energy is encompassed.According to a preferred embodiment, one or more control devices, whichwith particular preference can be operated by way of a common controlpanel, may be used for performing the control. The control by thesedevices may be realized here semi-automatically or fully automatically.Preferably, the control may be assisted here by the use of a computersystem. Return signals may be taken into consideration here in thecontrol, so that the control can also be interpreted as meaning feedbackcontrol.

According to a preferred embodiment, the at least two apparatuses forgenerating heat, to be specific the apparatus for the oxidation of ahydrocarbon-containing gas and the apparatus for providing heat by usingelectrical power, are preferably designed such that they have goodswitchability. Furthermore, these apparatuses are distinguished by goodreproducibility of the control.

The control of all the units may preferably be performed here jointly,in particular centrally, so that the internals for controlling theunits, in particular the apparatus for the oxidation of ahydrocarbon-containing gas and the apparatus for providing heat by usingelectrical power, have devices which make communication possible. Knowninterfaces and data transmission devices may be used for this purpose,such as a LAN (Local Area Network), the Internet or other digital oranalog networks.

The control of the at least two apparatuses for generating heat, to bespecific at least one apparatus for the oxidation of ahydrocarbon-containing gas and at least one apparatus for providing heatby using electrical energy, also synonymously referred to here aselectrical power, may take place in dependence on many differentfactors. These include, inter alia, the supply of electrical energy, thesupply of gas and the load of the electricity transmission network.

Gas is usually supplied and traded in long-term contracts, so that thesupply of gas can often be regarded as constant. However, in exceptionalcases, for example when there is a technical defect, or in exceptionalsituations, for example of a political nature or when there is anenormously high consumption by the generating countries themselves, thegas supply may turn out to be low in an unplanned way. Accordingly, themethod of the present invention leads to an improvement in the securityof supply in exceptional situations.

According to a particular embodiment of the present invention, the useof electricity is preferably chosen in dependence on the supply ofelectrical energy. Here it should be stated that, when there is a highproportion of renewable energy sources for obtaining electricity, strongfluctuations in the electricity supply can be expected, since, asexplained in more detail in the introduction, solar and wind energycannot be provided on a planned basis over a relatively long timescale.

A preferred embodiment of the method of the present invention comprisesthe following steps:

-   a) determining the supply of electrical energy,-   b) use of the electrical energy for generating heat if the supply    exceeds a predetermined value,-   c) use of gas for generating heat if the supply is below the    aforementioned predetermined value.

The supply of electrical energy may be established for example by way ofthe frequency of the AC network, an oversupply existing when there is afrequency that is too high, so that heat is generated with electricity.When there is a frequency that is too low, gas is used with preferencefor heat generation. In Europe, the AC network operates at approximately50.00 Hz, in the United States at 60.00 Hz. To maintain thesefrequencies, supplies of control power or control energy are provided independence on a frequency deviation, the responsibility for this beingborne by the network operator, which in turn obtains control power orcontrol energy from companies. A detailed description of this can befound, inter alia, in the Netztechnik/Netzbetrieb [networktechnology/network operation] forum of the VDE (FNN) “Transmission Code2007” of November 2009.

Furthermore, the supply of electricity can be determined by way oftrading platforms and/or by OTC methods and an associated electricityprice. In the case of a low electricity price on account of a highsupply, electrical energy can accordingly be used for heat generation.The price of gas necessary to generate a comparable amount of heat maybe used here as a threshold. The trading platforms that can be usedinclude in particular electricity exchanges, such as for example theEuropean Energy Exchange (EEX). OTC (over-the-counter) methods refer totrading methods that are enacted outside of exchanges.

If the price for obtaining a specific amount of thermal energy from gasis lower than the price for electrical energy, gas is generally used forheat generation. If the price for obtaining a specific amount of thermalenergy from electrical energy is lower than from gas, electricity isused for heat generation. If the price is identical, heat can beobtained with gas, with electricity or a mixture of the twopossibilities. In the price determination, it is necessary of course totake into consideration related costs, such as for example costs for thestorage of gas, servicing costs for the apparatuses, etc.

Preferably, an amount of thermal energy to be provided within a specifictime period or at a specific time may alternatively be provided byburning gas and/or by using electrical energy. Accordingly, theelectrical energy is preferably not merely converted into heat whenthere is a surplus, but when there is an actual demand that existsduring a predetermined time period and/or at a specific time. Thisallows the storage capacity of the heat reservoir to be minimized, whilein particularly preferred cases no additional reservoir has to be usedas a result of implementing the present method.

For example, it may be provided that the specific time period withinwhich an amount of thermal energy is to be provided is at most 24 hours,preferably at most 12 hours, with particular preference at most 6 hoursand with special preference at most 1 hour. These time periods may alsorecur, possibly one after the other for a sustained time. What isimportant, however, is that heat is only provided when there is anactual demand, the time component of the demand being taken intoconsideration.

The supply of electrical energy may preferably be determined just beforethe provision of thermal energy. It may preferably be provided that thedecision with regard to the type of provision of the thermal energy istaken at most 12 hours, preferably at most 6 hours, with particularpreference at most 2 hours and with special preference at most 1 hourbefore the time period and/or the point in time over which or at whichthe thermal energy is to be provided.

Customary market enquiries can be used for determining the supply ofelectrical energy, so that the decision on whether a predeterminedamount of thermal energy is provided by way of electrical energy or theburning of hydrocarbon-containing gas is dependent on an actual supplyprice. Surprising advantages can be achieved, however, by predictions ofthe supply of electricity being produced. In connection with theaforementioned renewable energy sources, data of weather forecasts maybe used in particular. Furthermore, historical data on the demand orconsumption of electrical energy may be used, in order to predict apossible surplus of electrical energy that can be used for the provisionof thermal energy.

The data on historical consumption may comprise for example the dailyvariation, the weekly variation, the annual variation and furthervariations in terms of the electricity demand. The data on theconsumption forecast may also take into consideration specific changes,for example the accession or discontinuation of a major consumer.

The data on the weather forecast may be produced over a time period ofany desired length, but the reliability of the forecast data decreasesover longer time periods. Therefore, the forecasts mentioned are usuallyproduced for a time period of 30 minutes to 2 months, preferably 1 hourto 1 month, with particular preference 2 hours to 14 days and withspecial preference 24 hours to 7 days.

The preparation of the forecast may take place at any time before thetime period to which the forecast applies, but the reliability isreduced if it is produced at a very early time. If the forecast isproduced very late, however, the options for influencing a change arereduced. According to a preferred embodiment, therefore, many forecastsare carried out at relatively short intervals, where the respectiveresults should be understood as instructions for future action, so thatalmost continuous adaptation can be achieved. Thus, when there is adeviation from an earlier forecast in the actual consumption values orthe power output that is provided by the renewable energy, an adaptationof the energy source used for the generation of the necessary thermalenergy is performed. This allows the achievement of a very short-termadaptation of the source that is expediently used for the generation ofa required amount of thermal energy, without having to do without theadvantages of an early offer to take electrical energy being issued thatby the use of forecast data, in particular weather forecasts and/orconsumption forecasts.

According to a further embodiment of the present invention, the use ofelectrical energy may be chosen in dependence on the load of theelectricity transmission network. This embodiment of the methodaccording to the invention makes it possible to efficiently relieve theload on the electricity transmission networks, which preferably operateat high voltages. This problem occurs in particular on account of thegeographically fixed nature of electricity generating plants that arebased on wind or solar energy. In this connection, reference is made inparticular to the high costs and the approval procedure that areinvolved in the construction of new transmission networks forelectricity.

It may preferably be provided that the method comprises the followingsteps:

-   a) determining the load of the electricity transmission network,-   b) use of the electrical energy for generating heat if the load of    the electricity transmission network exceeds a predetermined value,-   c) use of gas for generating heat if the load of the electricity    transmission network is below the aforementioned predetermined    value.

The load of the electricity transmission network relates here inparticular to the load of the lines that make up the electricitytransmission network. The load of the lines connecting locations of highelectricity generation to locations of high electricity demand should betaken into consideration here. Generally, there may be multiple linesbetween these locations, possibly using multiple node points. What isimportant is that the load of all the possible transmission paths is atsuch a level that electrical energy or electrical power can take placeonly at the expense of temporary overload of the transmission lines. Inthis respect it should be stated that the transmission lines areauthorized for a specific current and voltage, the admissible currentand voltage values being determined by the type of line, in particularthe diameter and/or the insulation of the transmission line. If the loadis too high, i.e. there is a current intensity that is too high, thetemperature of the line increases, so that damage to the line may befeared. Accordingly, these lines are produced for particularspecifications that are known to the network operator, for example thedistribution network operator and/or the transmission network operator.

Accordingly, load can be determined in a customary way, it beingpossible for example to use the temperature of the transmission lineand/or the present current intensity. The current intensity may bemeasured here for example by way of induction. The transmission networkoperator may allow short-term instances of overload.

The aforementioned predetermined value that serves for deciding on thetype of heat generation may depend here on the requirements of thenetwork operator and the access possibilities to the electricitynetwork. Accordingly, the predetermined value may lie within a widerange. Preferably, this value may be at least 70%, with preference atleast 80%, with particular preference at least 90% and with specialpreference at least 95% of the maximum continuous load capability of theelectricity network. The maximum continuous load capability of theelectricity network represents here the load capability in terms of thecurrent intensity and voltage of the respective transmission line thatis maintained over a time period of at least 20 h without causing anymeasurable, permanent damage to the transmission line. This maximumcontinuous load capability is generally known to the network operatorand may be dependent on weather conditions. At a high ambienttemperature, the transmission line can generally transmit a lowercurrent intensity.

The present invention surprisingly allows a hydrocarbon-containing gasto be provided, this gas being obtained by avoided oxidation. The term“providing” means within the scope of the invention that the gas that isnot oxidized can be used for other purposes. These other purposesinclude, inter alia, storage of the gas that is not oxidized, deliveryof the gas that is not oxidized to other customers and use of the gasthat is not oxidized as a raw material, for example in the chemicalindustry for the production of hydrogen cyanide (HCN), carbon disulphide(CS₂) and methyl halides.

Surprisingly, the present invention succeeds in increasing the realoption value. Real option value is understood within the scope of thepresent invention as meaning the possibility of using a specific poweroutput or energy technically in a wide variety of ways. These diversepossibilities for use allow an improvement to be achieved in thecost-effectiveness of the apparatuses and facilities that are used.

Thus, it may be envisaged, inter alia, to use the method for balancingout or mitigating fluctuations that occur due to renewable energysources, in particular due to the use of wind power plants. For example,a customer may be offered the feeding in of a specific, constant powerinto the electricity network, while higher power, occurring when thereare strong winds, is used for the generation of thermal energy by theuse of electricity as a result of the use of the present method. Thisallows the plannability of the network load to be improved.

Furthermore, the method may be used to provide control power or controlenergy to the operators of electricity transmission networks. As alreadyexplained above, the frequency of an AC network depends on the balancebetween power fed in and power drawn. When there is a surplus of powerfed in, the frequency increases, when too much power is drawn, thefrequency falls. To stabilize the network frequency to a predetermineddesired frequency, accordingly balancing power outputs are required ifunforeseeable events occur. These include for example power plantoutages, interruptions in the electricity transmission network or adiscontinuation of major consumers on account of unexpected defects.This desired frequency is currently 50.00 Hz in Europe and 60.00 Hz inthe US, while these figures do not restrict the present invention.

To balance out insufficient feeding of energy into the network, i.e. afalling frequency, positive control energy is required, where this canbe provided by increasing the feeding in, for example by increasing thepower output of an electricity power plant, or by reducing the amounttaken by certain consumers, generally major customers.

Negative control energy, which is required when there is a frequencythat is too high, can be provided by reducing the feeding in, forexample by reducing the power output of an electricity power plant, orby increasing the amount taken by certain consumers, generally majorcustomers.

At present, three different types of control power are defined in Europeby the valid regulations, which are defined more specifically inparticular by the UCTE (Union for the Co-ordination of Transmission ofElectricity) or the organization succeeding it, the ENTSO-E (EuropeanNetwork of Transmission System Operators for Electricity).

In the currently applicable code of practice (UCTE Handbook), therespective requirements and types of control power are also specified.The types of control power have for example different requirements withregard to the time response to a frequency deviation. Furthermore, thetypes of control power defined so far differ in the time for which poweris delivered. Furthermore, various boundary conditions apply with regardto the use of control power.

Thus, in Europe, primary control power, secondary control power andminutes reserve power are defined by the aforementioned associations.Primary control power (PCP) is delivered Europe-wide by all the sourcesinvolved independently of the place of origin of the disturbance. Theabsolute maximum power has to be delivered when there are frequencydeviations of minus 200 mHz and below (in absolute terms), the absoluteminimum power has to be delivered when there are frequency deviations ofplus 200 mHz and above. In the range between 10 mHz and 200 mHz, theprimary control power is provided largely in proportion to the frequencydeviation at the particular time. From the non-operative state, therespective maximum power (in terms of the absolute amount) must beprovided within seconds. The primary control power is usually procuredby the network operator through a market, where for example power plantoperators or major electricity customers offer the corresponding primarycontrol power.

By contrast with the primary control reserve, the secondary controlreserve is not provided commonly in the European association, butseparately in each control zone by the respective transmission networkoperator. Secondary control power (SCP) and minutes reserve power (MRP)are intended to compensate as quickly as possible for disturbances andconsequently ensure that the frequency is restored as quickly aspossible to the desired range, preferably at the latest after 15minutes. With regard to the dynamics, lower requirements are stipulatedfor the SCP and MRP (5 minutes and 15 minutes, respectively, before fullpower is delivered after activation); at the same time, these poweroutputs must also be provided over longer time periods than primarycontrol power. More details on this can be can be found, inter alia, inthe Netztechnik/Netzbetrieb [network technology/network operation] forumof the VDE (FNN) “Transmission Code 2007” of November 2009.

Generally, the suppliers of control power must pass a prequalificationprocedure, in which the requirements are specifically set out.

The present method can, inter alia, serve the purpose of offeringprimary control power. At present, this must be offered symmetrically,such that a supplier must deliver both positive control power andnegative control power. In connection with the present method, forexample, a controllable electricity consumer may be used in combinationwith the aforementioned units for generating thermal energy. Thecontrollable electricity consumers include in particular industrialplants that can be cut back in their electricity consumption whenpositive control power is provided. Aluminium plants or otherelectrolysis plants may be mentioned, inter alia, by way of example.When negative control power is provided, thermal energy obtained byelectricity instead of by oxidation of gas is preferably used.Furthermore, it may also be envisaged to continuously use a specificelectrical power output for generating heat, which is possiblysubstituted by the use of gas if positive control power is to beprovided. In the case of providing negative control power, the heatingcapacity provided by electrical energy is increased. Accordingly, thismethod is preferably distinguished by the fact that both apparatusesgenerate heat at the same time, so that heat is generated by theoxidation of a hydrocarbon-containing gas and the use of electricalenergy simultaneously over a certain time period. Depending on thecontrol power to be provided, the oxidation of gas is reduced (negativecontrol power) or increased (positive control power).

The currently valid regulations in Europe prescribe for example offeringa band that is at least +/−1 MW wide, this power having to be offeredfor a time period of at least one week. The values mentioned can beincreased by an integral multiple, so that for example a band of +/−2 MWmay also be offered. The electrical power may in turn be generated bythe operator of the method itself or be purchased on the energy market.

Furthermore, the present method may be used in order to offer secondarycontrol power. Secondary control power is offered or provided with lowerdynamics. Here, the transmission network operator (Transmission SystemOperator, TSO for short) undertakes the control of the system with whichcontrol power is provided. At present, in Europe it is approximatelyevery 3 seconds that the transmission network operator prescribes adesired power value that has to be provided by the supplier. With regardto the currently applicable methods, a power output of 5 MW positive or5 MW negative must be offered over a time period of at least one week,it likewise being possible of course for integral multiples of thesevalues, such as 10 MW, 15 MW or 30 MW, of positive or negative controlpower to be offered. It should be stated that these values are given toillustrate the present invention, without any restriction as a resultbeing intended.

With regard to the delivery of negative control energy, it should bestated that the unit for generating heat by electrical energy mustdeliver these power values individually or by a common group of multipleunits in order to be able to offer this power. In the case of thedelivery of negative secondary control energy, that is to say takingenergy from the network, there is accordingly a switchover fromgeneration of heat by the oxidation of gas to corresponding generationof heat by the use of electrical energy. On the other hand, positivesecondary control energy may also be delivered, where in this case thereis a changeover from generation of heat by electricity to gas heating.It should once again be pointed out that a negative secondary controlpower may also be provided and offered, without a simultaneous offer ofpositive secondary control power being necessary. Furthermore, theprovision of positive and negative secondary control power may bejointly offered.

Furthermore, the present method is also suitable in conjunction with thedelivery of minutes reserve power. In a way similar to the previousdescription with regard to the provision of secondary control power,minutes reserve power as negative control power can be offered anddelivered independently of positive minutes reserve power. Accordingly,the statements made above with regard to the secondary control poweralso apply with respect to the provision of minutes reserve power.

Differences arise in particular with regard to the offering method andthe duration of the power to be delivered. Minutes reserve power isoffered in time periods of approximately 4 hours, the present methodsproviding that the auctions take place on the previous day. According tothe currently valid regulations, power outputs of at least 5 MW andintegral multiples thereof are offered.

The aforementioned statements with regard to the current regulations aremade to illustrate the surprising improvements, without any restrictionas a result being intended.

The aforementioned real option values that are made possible by thepresent invention are to be set out once again in an abstracted form.

Surprisingly, a contribution to network stabilization can be made by thepresent invention even when there are unexpected fluctuations, and thislowers the environmental impact, in particular reduces carbon dioxideemissions. This advantage is made possible by the provision or storageof electrical energy in the form of hydrocarbon-containing gas, whichwithout the present method would have led to a release of carbondioxide. Here, the provision of negative control power is preferred,since this does not necessitate sustained use of electrical energy.Thus, negative control power can be offered and delivered without beingcombined with a major consumer of electrical energy. Positive controlpower can likewise be provided. However, this requires sustained use ofelectrical energy for the generation of heat, or a consumer ofelectrical energy that is controllable, in particular can be cut back.Consumers that can be cut back particularly include in this contextindustrial plants that can be cut back in output, such as for exampleelectrolysis plants or aluminium plants.

The provision of energy is also necessary in the gas network, in orderto balance out differences between forecast demand and actual demand forgas. Generally, control energy in the gas network is understood asmeaning the energy that is necessary for physically balancing out a gasnetwork, the balancing being the responsibility of the gas networkoperator.

Disequilibria to be balanced out are generally referred to as balancingenergy.

The present method can accordingly be used to make control energyavailable to a gas network operator. When there is a surplus, i.e. avery high pressure in the network, according to the present inventiongas can be used for providing thermal energy, while, when there is ashortfall of gas in the gas network, electrical energy is used forobtaining heat.

A particularly preferred embodiment of the method of the presentinvention is distinguished by the fact that the hydrocarbon-containinggas provided is stored. The use of a gas reservoir allows theaforementioned real option values to be combined, so that the method canbe used for providing control energy for the electricity transmissionnetwork and at the same time for providing control energy for the gasnetwork. Simultaneously occurring contributions of energy, i.e. feedingof gas into the gas network and of electrical power into the electricitynetwork, can be secured here, where in this case gas from the gasreservoir is used to meet the obligation. Furthermore, gas obtained whenthere is a take-up of electrical energy in the case of the provision ofnegative control power for the electricity network can also be securedwhen there is a surplus supply of gas, i.e. a low gas price or a controldemand for negative control energy, in the gas network.

The use of a gas reservoir accordingly allows the achievement oftemporal decoupling of the time at which the gas is obtained from thetime at which the gas is used, leading to an unexpected increase in thepossibilities that have been discussed above.

The hydrocarbon-containing gas provided may be stored in an overgroundreservoir and/or underground reservoir. With regard to undergroundreservoirs, cavern storage facilities and pore storage facilities may bementioned, inter alia. Pore storage facilities are very inexpensive tomaintain, but have disadvantages in terms of how gas is fed in andretrieved. Furthermore, in the case of an underground reservoir it isnot possible for the entire gas that is fed in to be retrieved undercost-effective conditions, with pore storage facilities generally havingdisadvantages in comparison with cavern storage facilities in thisrespect, the gas concerned being known as cushion gas and oftenreflected in the costs of a gas reservoir. Pore storage facilities areoften set up in depleted natural gas and/or oil fields. Furthermore,layers of rock that contain water and the water of which can bedisplaced by gas (aquifers) are suitable for the provision of porestorage facilities. Cavern storage facilities are set up in layers ofrock (rock caverns) and rock salt formations (salt caverns).

Overground reservoirs are often provided with technical measures thatreduce the volume requirement. For example, the gas may be stored asliquefied gas at low temperatures or at high pressure.

Among the most well-known overground reservoirs are spherical gas tanks,which operate under high pressure. With a diameter of the steel sphereof 40 m, a design for 10 bar is expedient, while pressures of up to 20bar can also be realized if there is a correspondingly thick wall.

Pipe storage facilities are set up underground at a shallow depth, ahydrocarbon-containing gas, in particular natural gas, at a pressure ofup to 100 bar being stored in pipes, which are preferably arranged inparallel.

Overground reservoirs, which on account of the shallow depth alsoinclude pipe storage facilities, are distinguished by a very highfeed-in and retrieval rate. Accordingly, these reservoirs are suitablein particular for the provision of control energy for the gas network.

According to a particularly preferred embodiment, a combination of theaforementioned reservoirs, in particular a combination that comprises atleast one overground reservoir and at least one underground reservoir,may be used, so that the advantages of overground reservoirs andunderground reservoirs can be combined.

The spatial separation of all the apparatuses and component parts of afacility for carrying out the method according to the invention is notsubject to any particular limitations. However, as already explained,the heat provided by the unit for generating thermal energy fromelectrical energy must be capable of substituting the thermal energythat is obtained by oxidation of gas. Accordingly, this requires aspatial proximity, but it is quite possible for the units to be severalkilometres apart in industrial plants.

Furthermore, it may be provided that the hydrocarbon-containing gasprovided is stored in spatial proximity to the apparatus for theoxidation of a hydrocarbon-containing gas. This embodiment of the methodaccording to the invention surprisingly succeeds in ensuring minimalload of the gas network, so that on the one hand no entry-exit fees orother charges for using the gas network due to the lower consumptionhave to be paid. On the other hand, physical control over the gasobtained can also be ensured. This allows the provision of control gas,i.e. control energy, for the gas network to be ensured independently ofother control devices.

Preferably, it may be provided that the gas inlet to the reservoir is atmost 20 000 m, with preference at most 10 000 m and with particularpreference at most 5000 m away from the gas inlet of the apparatus forthe oxidation of a hydrocarbon-containing gas. For a combination ofmultiple apparatuses for the oxidation of a hydrocarbon-containing gas(pool of apparatuses for the oxidation of a hydrocarbon-containing gas),the distance to the apparatus for the oxidation of ahydrocarbon-containing gas that is at the smallest distance from thereservoir applies here, the figures referring to the distance in astraight line.

Furthermore, it may be provided according to another embodiment that thehydrocarbon-containing gas provided occurs with a spatial separationfrom the apparatus for the oxidation of a hydrocarbon-containing gas.This also allows storage devices that are bound to geographicalrequirements, such as the aforementioned porous and/or cavern storagefacilities, to be used for carrying out the present method. Preferably,it may accordingly be provided that the gas inlet to the reservoir is atleast 10 000 m, with particular preference at least 20 000 m and withspecial preference at least 50 km away from the gas inlet of theapparatus for the oxidation of a hydrocarbon-containing gas. For acombination of multiple apparatuses for the oxidation of ahydrocarbon-containing gas (pool of apparatuses for the oxidation of ahydrocarbon-containing gas), the distance to the apparatus for theoxidation of a hydrocarbon-containing gas that is at the smallestdistance from the reservoir applies here, the figures being based ondistances in a straight line.

According to a further embodiment of the present invention, at least onereservoir may be present nearby and at least one may be spatiallyseparate. According to this embodiment, there may be at least onereservoir where the gas inlet to the reservoir is at most 19 000 m, withparticular preference at most 10 000 m and with most particularpreference at most 5000 m away from the gas inlet of the apparatus forthe oxidation of a hydrocarbon-containing gas, and at least onereservoir where the gas inlet to the reservoir is at least 20 000 m andwith special preference at least 50 km away from the gas inlet of theapparatus for the oxidation of a hydrocarbon-containing gas. In such acombination, the shortest distance applies to the reservoir nearby andthe greatest distance applies to the reservoir that is spatiallyseparate, the figures being based on distances in a straight line.

According to a further embodiment, the hydrocarbon-containing gasprovided may be stored in the natural gas pipeline network by raisingthe pressure.

The source of the electrical energy that is used for carrying out thepresent method is not critical. Accordingly, the electrical energy maybe generated by nuclear power plants, coal power plants, gas powerplants, wind power plants and/or solar power plants.

According to a preferred embodiment, the electrical energy that isalternatively used for providing heat may originate at least partiallyfrom renewable energy sources, for example from wind power and/or solarenergy.

However, it should be noted that, according to current legislation,electricity that has been obtained from renewable energy sources may befed into the electricity network even without any specific demand andmust be paid for. Accordingly, conventionally generated electricity mayat times constitute a “surplus”, since it may be less profitable for apower plant operator to throttle a power plant than to sell electricitybelow the cost price. This electrical energy obtained from the continuedoperation of conventional plants can surprisingly be used for obtaininghydrocarbon-containing gas.

The thermal energy provided by an apparatus for providing heat by usingelectrical power or an apparatus for the oxidation of ahydrocarbon-containing gas can be used variously. Preferably, it can beused for increasing the temperature of a liquid. Furthermore, it may beprovided that the heat generated from electrical energy and/or byoxidation of gas increases the temperature of a liquid by at least 10°C., preferably at least 30° C., with particular preference at least 60°C. The temperatures are based here on the difference between the inlettemperature of the liquid entering the apparatus and the outlettemperature of the liquid.

According to a preferred embodiment, the thermal energy may serve forgenerating steam. Here, the apparatus for the oxidation of ahydrocarbon-containing gas may comprise in particular a device that canprovide gas. Surprising advantages can be achieved if the apparatus forproviding heat by using electrical power likewise generates steam. Bysurprisingly simple and low-cost modifications, it is possible in thisway to upgrade existing facilities, for example in industry, inparticular the chemical industry, for carrying out the present method,without extensive internals and controls having to be installed in thevarious sections of the facilities.

The present method can be used in all areas in which heat is generatedby oxidation of gas. These include heating systems in single-family ormulti-family dwellings, communal supply installations that for exampleprovide district heating, and large-scale industrial plants, inparticular chemical plants.

Surprising advantages can be achieved in particular in the case ofmethods that are used in conjunction with the generation of chemicalproducts. In many plants, steam is centrally generated from oxidation ofgas and subsequently used for heating pipelines, boilers or evaporators.When electrical energy is used for the provision of heat, the presentmethod can be modified in a manner that the necessary heat is feddirectly to the devices or components to be heated, such as for examplepipelines, boilers or evaporators. This may take place by the use ofmicrowaves, by induction and/or by resistance heating. This surprisinglyallows energy to be conserved, since the use of steam lines causes heatlosses. This advantage is possible as a result of the very precisetemperature setting and the easily controllable heat distribution of thedevices or components heated by electricity.

Furthermore, the present method may be carried out in particular incombination with a combined heat and power generating plant, preferablya unit-type cogenerating plant, as explained above. Relatively smallelectricity generators that are operated with gas may be used here inparticular, providing electricity and heat for single-family dwellings,residential buildings, relatively small businesses and hotels on adistributed basis. These combined heat and power generating plantspreferably have a capacity of less than 100 kW, with particularpreference less than 75 kW and with special preference less than 50 kW.These plants may be used multiply in an interconnected group, so thatthere is a common control system, which may be realized centrally ordecentrally. The total capacity of the interconnected group is notsubject to any limitation here, so that total capacities of at least 1MW, preferably at least 5 MW, with particular preference at least 50 MWand with most particular preference at least 100 MW can be realized,this capacity representing the rated capacity under full load.

Furthermore, the present invention concerns a facility for carrying outthe present method that is characterized in that the facility comprisesat least one consuming entity with at least one device to be heated, atleast one apparatus for the oxidation of a hydrocarbon-containing gasand at least one apparatus for providing heat by using electrical power,the device to be heated being designed such that it can be heated bothby the apparatus for the oxidation of a hydrocarbon-containing gas andby the apparatus for providing heat by using electrical power, and thefacility comprises at least one control device which is connected viadata lines to the apparatuses for generating heat and to a means fordetermining the demand for thermal energy, the means for determining thedemand for thermal energy being in connection with the device to beheated.

The term consuming entity should be understood within the scope of thepresent invention in a broad sense, and can be for example asingle-family dwelling, a multi-family dwelling, a small business or anindustrial plant. A consuming entity comprises at least one device to beheated. This device depends on the type of consuming entity, the deviceto be heated being connected to the two apparatuses for generating heat,to be specific at least one apparatus for the oxidation of ahydrocarbon-containing gas and at least one apparatus for providing heatby using electrical energy. The type of connection may be designed verydifferently depending on the consuming entity, so that these apparatusesfor generating heat may be arranged directly in a device to be heated orat least one of the apparatuses for generating heat may be connected toa device to be heated, for example by at least one steam line or someother heat-carrying line.

The devices to be heated include, inter alia, heating boilers that canbe heated with a gas burner and/or a heating coil. In an industrialplant, for example, a steam generator operated with gas may providesteam for various parts of the plant, for example stills, reactors orpipelines, where these parts of the plant can respectively be heated byheating coils, by microwaves or induction.

The method of the present invention may be carried out with preferencewith a facility which, in addition to an apparatus for the oxidation ofa hydrocarbon-containing gas and an apparatus for providing heat byusing electrical power, comprises a control device.

The control device is preferably connected, inter alia, to the apparatusfor the oxidation of a hydrocarbon-containing gas and the apparatus forproviding heat by using electrical power, so that data can be exchanged.This data exchange may take place by customary means and methods thathave been previously mentioned. Furthermore, the control device may beconnected to a sensor, for example a temperature sensor, whichdetermines the heat requirement of a consuming entity.

The control device may be connected here to individual components of thefacility by one line each. Furthermore, these components may howeveralso be connected to the control device via a single line. In this case,one or more distributors, which can collect appropriate data of theindividual components and pass it on to the control device, may beprovided for example.

Further properties of the control device, in particular the design as acomputer system and the embodiment where the control device is equippedwith communication devices, have already been described, so reference ismade thereto.

Preferably, the facility may comprise a gas reservoir. In thisembodiment, it may be provided with preference that the control deviceis connected via a data line to a valve, which is installed in the gasline that supplies the apparatus for the oxidation of ahydrocarbon-containing gas with gas and can divert gas into the gasreservoir when electricity is used for generating heat.

According to a further embodiment, the facility of the present inventionmay comprise multiple consuming entities, for example single-family ormulti-family dwellings or small businesses. The heating system of theconsuming entities respectively comprises an apparatus for the oxidationof a hydrocarbon-containing gas and an apparatus for providing heat byusing electrical power as well as a device to be heated. In thisembodiment, these components are preferably controlled by a commoncontrol system via data lines. In particular, a heat requirement istransmitted to the control device, which may be determined with asensor, for example a temperature sensor. For the provision of thisthermal energy, the control device may transmit corresponding controlsignals to the apparatus for the oxidation of a hydrocarbon-containinggas, to the apparatus for providing heat by using electrical power or toboth apparatuses.

Furthermore, it may be provided that the facility has a means fordetermining the demand for thermal energy, this means preferably beingconnected to the aforementioned control device. Furthermore, the meansfor determining the demand for thermal energy may be in connection withthe device to be heated. This connection to the device to be heated isnot subject to any specific limitation, but arises from the method ofdetermination with which the means determines the heat requirement.These means include in particular sensors, for example temperaturesensors, and heat-requirement measuring devices or other control unitsfor setting a predetermined temperature or a predetermined temperaturerange.

Preferably, this means for determining the demand for thermal energy orthe control system may be provided with a unit which calculates from thedata that is provided by this means for determining the demand forthermal energy as well as further data, for example historical data onthe historical consumption, data on the heat capacity and the finaltemperature to be achieved or production data of chemical plants, anamount of thermal energy to be provided, which is alternatively providedby way of the oxidation of a hydrocarbon-containing gas or the use ofelectrical energy.

Alternatively, it is sufficient that the means for determining thedemand for thermal energy transmits a heat requirement to the controlsystem and, when a predetermined temperature is achieved, likewisereports this event, it being possible in this way for feedback controlto be achieved. The thermal energy respectively required for theheating-up operations may be provided in each case of need specificallyby the oxidation of a hydrocarbon-containing gas and/or by electricity.

A timely response to the offer to supply electricity and thesubstitutability give rise to advantages, in particular that of a smallsize of a possible heat reservoir. Thus, a preferred facility with whichthe method is carried out does not require a heat reservoir that canstore more than the heat requirement for a week or more. Preferably, theheat storage capacity is at most 200% of the heat requirement for oneday, with particular preference at most 100% and with particularpreference at most 50%.

Further embodiments of the facility have previously been described withrespect to the method, so reference is made thereto.

Exemplary embodiments of the invention are explained below on the basisof three schematically represented figures, without thereby restrictingthe invention. In the figures:

FIG. 1 shows a schematic representation of a first embodiment of afacility according to the invention for carrying out the present method;

FIG. 2 shows a schematic representation of a second embodiment of afacility according to the invention for carrying out the present methodand

FIG. 3 shows a flow diagram for an embodiment of a method according tothe invention.

FIG. 1 shows a schematic setup of a preferred embodiment of a facilityfor carrying out the method according to the invention. This facilitycomprises a consuming entity 1, where this may for example be anindustrial plant, the heat requirement of which can be coveredalternatively by way of an apparatus for the oxidation of ahydrocarbon-containing gas 2 and/or an apparatus for providing heat byusing electrical power 3. The apparatus for the oxidation of ahydrocarbon-containing gas 2 is supplied with fuel by a gas line 4,whereas the apparatus for providing heat by using electrical power 3 isconnected to an electricity line 5. The apparatuses for generatingthermal energy heat up a device to be heated 6, the presentrepresentation being very schematic. In a household, for example, aheating boiler may be a device to be heated 6, which can be heated witha gas burner and/or a heating coil. In an industrial plant, a steamgenerator operated with gas may for example provide steam for variousparts of the plant, for example stills, reactors or pipelines, it beingpossible for these parts of the plants respectively to be heated withheating coils, by microwaves or induction. The device to be heated 6 isaccordingly connected to the two apparatuses for generating heat 2, 3,it being possible for this connection to be designed in very differentways, so that these apparatuses for generating heat 2, 3 may be arrangeddirectly in a device or these apparatuses for generating heat 2, 3 mayfor example be connected to the device to be heated 6 by steam lines orother heat-carrying lines, as explained above by way of example.

The present facility also comprises a control device 7, which isconnected via data lines 8, 8′ and 8″ to the apparatuses for generatingheat 2, 3 and a means for determining the demand for thermal energy,which is not represented for reasons of overall clarity. The means fordetermining the demand for thermal energy is in turn connected to thedevice to be heated 6. This connection is dependent on the method ofdetermining the heat requirement. The means for determining therequirement for thermal energy may be designed, inter alia, as a sensor,for example as a temperature sensor, which measures the temperature ofthe device to be heated and transmits this measurement result to thecontrol device 7.

The embodiment presented here shows one line respectively to theindividual components, but these components may also be connected to thecontrol device via a single line. In this case, one or moredistributors, which can collect appropriate data of the individualcomponents and pass it on to the control device 7, may be provided forexample. With a further data line, the control device 7 is connected toa valve 10, which is installed in the gas line 4 and can divert gas viathe line 11 into a gas reservoir 12 when electricity is used forgenerating heat.

Usually, gas is for example bought under long-term contracts and usedfor providing heat, the heating method being changed over such that gascan be provided when there is a great supply of electricity. This gas isin the present case transferred to the reservoir 12 and can be used forvarious purposes, which have been explained above. For example, gas maybe offered as control energy on the gas market. Furthermore, the gas maybe sold, in particular when the price is high.

In FIG. 2, a further embodiment of a facility for carrying out thepresent method is schematically represented, the apparatuses forgenerating heat that have previously been explained in more detail notbeing described for reasons of overall clarity. FIG. 2 shows variousconsuming entities 20, 20′ and 20″, which are respectively connected bya gas line 24 and an electricity line 25. The consuming entities 20, 20′and 20″ may for example be single-family or multi-family dwellings orsmall businesses. The heating system of the consuming entities 20, 20′and 20″ has of course at least one apparatus described in more detail inFIG. 1 for the oxidation of a hydrocarbon-containing gas and anapparatus for providing heat by using electrical power as well as adevice to be heated. These components are controlled by a control system29 via data lines 30, 30′ and 30″, which connect the control device 29to the respective consuming entities 20, 20′ and 20″. In particular, aheat requirement is transmitted to the control device 29, which isdetermined with a corresponding means and can be determined with asensor, for example a temperature sensor. For the provision of thisthermal energy, the control device 29 may transmit corresponding controlsignals to the apparatus for the oxidation of a hydrocarbon-containinggas, to the apparatus for providing heat by using electrical power or toboth apparatuses. The amount of gas made available by the use ofelectricity can be withdrawn from the gas network via the gas conduit 31and stored in the gas reservoir 32, and be provided.

In FIG. 3, a flow diagram for a preferred method of the presentinvention is presented. In step 1, the amount of thermal energy to beprovided is determined. The method of determination to be used for thiscan be chosen to be very simple, for example by measuring thetemperature of a component or by a liquid. If the actual temperature isless than the desired temperature, thermal energy is required, and isprovided in the following method steps. In advanced embodiments, a meansfor determining or predicting the required amount of energy may be usedfor this, for example a computer which calculates the required amount ofelectrical energy from the difference between the actual temperature andthe desired temperature and transmits to the control device the amountof electrical energy or chemical energy in the form of gas that isrespectively required to achieve the intended desired temperature.

In step 2, the supply of electrical energy is determined. Thisdetermination may take place with a computer system which enquiresappropriate data from electricity exchanges or takes into considerationdata correspondingly provided by the electricity exchanges. Furthermore,as already explained above, the electricity supply may also take theform of the provision of control energy, in particular negative controlenergy.

If the supply of electrical energy is low, the energy to be provided isgenerated by oxidation of a hydrocarbon-containing gas, as stated instep 5. When there is a great supply of electrical energy, it may beenquired in an optional step 4 whether there is an exclusion criterionfor the use of electricity. This may for example take the form of adefect of the apparatus for providing heat by using electrical power.However, overload of the electricity network may also favour the use ofgas. If there is an exclusion criterion, the thermal energy to beprovided is generated by the use of gas, as provided by step 5 accordingto the present flow diagram.

If there is no exclusion criterion, according to the present flowdiagram the heat to be provided is created by the use of electricalenergy.

The features of the invention that are disclosed in the descriptionabove and the claims, figures and exemplary embodiments may be essentialfor realizing the invention in its various embodiments both individuallyand in any desired combination.

1-30. (canceled)
 31. A method for obtaining a hydrocarbon-containinggas, comprising a generation of heat by operating an apparatus for theoxidation of a hydrocarbon-containing gas, wherein alternatively arequired provision of heat from the oxidation of thehydrocarbon-containing gas is substituted by the provision of heat fromelectrical energy with an apparatus for providing heat by usingelectrical power and the hydrocarbon-containing gas that is not oxidizedis provided.
 32. The method of claim 31, wherein thehydrocarbon-containing gas provided is stored.
 33. The method of claim32, wherein the hydrocarbon-containing gas provided is stored in areservoir selected from the group consisting of a pore storage facility,a cavern storage facility, a pipe storage facility, a sphericalreservoir or a combination thereof.
 34. The method of claim 32, whereinthe hydrocarbon-containing gas provided is stored in a natural gaspipeline network by raising the pressure.
 35. The method of claim 32,wherein the hydrocarbon-containing gas provided is stored in spatialproximity to the apparatus for the oxidation of a hydrocarbon-containinggas.
 36. The method of claim 35, wherein the gas inlet to the reservoiris at most 10 000 m away from the gas inlet of the apparatus for theoxidation of a hydrocarbon-containing gas.
 37. The method of claim 32,wherein the hydrocarbon-containing gas provided is stored with a spatialseparation from the apparatus for the oxidation of ahydrocarbon-containing gas.
 38. The method of claim 37, wherein the gasinlet to the reservoir is at least 10 000 m away from the gas inlet ofthe apparatus for the oxidation of a hydrocarbon-containing gas.
 39. Themethod of claim 31, wherein the electrical energy that is alternativelyused for providing heat originates at least partially from renewableenergy sources.
 40. The method of claim 31, wherein the use ofelectrical energy is chosen in dependence on the supply of electricalenergy.
 41. The method of claim 31, wherein the use of electrical energyis chosen in dependence on the load of the electricity transmissionnetwork.
 42. The method of claim 31, wherein an amount of thermal energyto be provided within a specific time period is alternatively providedby burning gas and/or by using electrical energy.
 43. The method ofclaim 42, wherein the specific time period within which an amount ofthermal energy is to be provided is at most 24 hours.
 44. The method ofclaim 42, wherein a decision with regard to the type of provision of thethermal energy is taken at most 12 hours before the time period withinwhich the thermal energy is to be provided.
 45. The method of claim 31,wherein the apparatus for the oxidation of a hydrocarbon-containing gascomprises a combined heat and power generating plant.
 46. The method ofclaim 31, wherein the ratio of the heating capacity achievable by gas tothe heating capacity that is provided by electrical energy lies in therange from 2:1 to 1:2.
 47. The method of claim 31, wherein a facilitywith which the method is carried out does not comprise a heat reservoirthat can store more than the heat requirement for a week.
 48. The methodof claim 31, wherein the electrical energy is transformed into heat byresistance heating.
 49. The method of claim 31, wherein the electricalenergy is transformed into heat by microwaves.
 50. The method of claim31, wherein electrical energy is transformed into heat by inductionheating.
 51. The method of claim 31, wherein the heat serves forgenerating steam.
 52. The method of claim 31, wherein the heat generatesa chemical product.
 53. The method of claim 31, wherein the method isoperated in a unit-type cogenerating plant.
 54. The method of claim 31,comprising the steps a) determining supply of electrical energy, b) useof the electrical energy for generating heat if the supply exceeds apredetermined value, and c) use of gas for generating heat if the supplyis below said predetermined value.
 55. The method of claim 31, whereinweather forecasting data is used for determining supply of electricalenergy.
 56. The method of claim 31, comprising the steps a) determiningthe load of an electricity transmission network, b) use of theelectrical energy for generating heat if the load of the electricitytransmission network exceeds a predetermined value, c) use of gas forgenerating heat if the load of the electricity transmission network isbelow said predetermined value.
 57. The method of claim 31, wherein theheat generated from electrical energy and/or by oxidation of gasincreases the temperature of a liquid by at least 10° C.
 58. A Facilityfor carrying out the method of claim 1, comprising at least oneconsuming entity with at least one device to be heated, at least oneapparatus for the oxidation of a hydrocarbon-containing gas and at leastone apparatus for providing heat by using electrical power, the deviceto be heated being designed such that it can be heated both by theapparatus for the oxidation of a hydrocarbon-containing gas and by theapparatus for providing heat by using electrical power, said facilityfurther comprising at least one control device which is connected viadata lines to the apparatuses for generating heat and to a measuringdevice determining the demand for thermal energy, said measuring devicebeing in connection with the device to be heated.
 59. The facility ofclaim 58, wherein the device to be heated is a heating boiler.
 60. Thefacility of claim 58, further comprising at least one gas reservoir.